The deadline for paper returns is 7 May, while online returns can be made until 28 May.

The tax is calculated on the value of the property and is self-assessed by the owner.

Almost 179,000 letters have been issued by the Revenue Commissioners in relation to the tax.

Minister for the Environment Phil Hogan said the changes to the exemption list reflected "the improvements made by local authorities in resolving problems in unfinished housing developments".

Minister of State for Housing Jan O'Sullivan also said that figures used to calculate the number of homes exempt from the household charge last year were inaccurate and have been updated for the new property tax.

Speaking on RTÉ's News at One, the minister said the apparent discrepancy in the two figures could be explained because considerable progress had been made in improving unfinished estates in the meantime, and there were also a number of ghost estates where there were no residents at all.

The Government made €5 million available to local authorities to improve estates.

Ms O'Sullivan said that only estates with seriously problematic issues have been exempted from the property tax.